The materials used in connectors and plugs mainly include metal contacts, insulators, housings, and auxiliary materials. Different materials are used for different parts to meet requirements such as conductivity, mechanical strength, corrosion resistance, and environmental adaptability.
1. Metal Contact Materials
Copper and copper alloys: The core material for manufacturing connector contacts due to their excellent electrical and thermal conductivity.
Brass (copper-zinc alloy): Good mechanical properties and low cost, commonly used in general power connectors.
Phosphor bronze (copper-tin-phosphorus alloy): Good elasticity and wear resistance, suitable for frequent plugging and unplugging scenarios, such as USB interface springs. C5191 phosphor bronze strip is of this type, with a tensile strength ≥635MPa, widely used in mobile phone and computer connectors.
Beryllium bronze: High strength, high elasticity, and corrosion resistance, used in high-end fields such as aerospace.
Placing Materials:
Gold plating: Chemically stable, does not oxidize, significantly reduces contact resistance, used in high-speed signal transmission equipment (such as servers).
Silver Plating:Offers the best conductivity but is prone to oxidation. Often used in cost-sensitive and environmentally friendly devices, such as audio plugs.
2. Insulator and Housing Materials:
Engineering Plastics:
PA (Nylon): Abrasion-resistant and chemically resistant, suitable for industrial environments.
PBT, PA6/PA66: Commonly used as sheath materials; glass fiber reinforcement or flame retardants can be added to improve performance.
LCP (Liquid Crystal Polymer): Used for high-density, miniaturized connectors, such as the insulator for XH2.54 terminals.
Polycarbonate (PC): Transparent and high-strength, suitable for fiber optic connectors where internal structure needs to be observed.
Metal Housing Materials:
Stainless Steel: High strength and corrosion-resistant, used in harsh environments such as outdoor and port equipment.
Aluminum Alloy: Lightweight, suitable for portable devices or applications where weight is a concern, such as laptop connectors.
Zinc Alloy, Magnesium-Aluminum Alloy: Commonly used in aerospace connectors; robust and durable.
3. Material Characteristics of Special Types of Connectors
Industrial Connectors: Use phosphor bronze gold-plated contacts and die-cast aluminum alloy housings, achieving an IP69K protection rating, suitable for vibration and humid environments.
Heavy-Duty Connectors (HDC): Use PBT, PA, or polycarbonate as insulators; the metal housing provides IP65 or higher protection, supporting mixed power, signal, and data transmission.
Explosion-Proof Connectors: Housings are made of cast aluminum alloy or 316L stainless steel, with sealing rings achieving IP68 protection, suitable for hazardous environments such as chemical and petroleum industries.
Aerospace Connectors: Contacts are mostly gold-plated; housings are made of magnesium-aluminum alloy or stainless steel, ensuring stable operation at extreme temperatures (-65℃ to 200℃).
